Cole Burton
Advisor: Prof. Robert Speyer

will defend a master’s thesis entitled,

Process Characterization of Hydrogen Direct Reduction of Stainless Steel Oxides

On

Wednesday, November 20 at 12 p.m.

MRDC Room 3510

Committee
            Prof. Robert Speyer – School of Materials Science and Engineering (advisor)
            Prof. Josh Kacher – School of Materials Science and Engineering
            Prof. Naresh Thadhani – School of  Materials Science and Engineering

Abstract

Fabrication of complex stainless-steel components using conventional melting and forming methods is often limited by geometric constraints, high energy consumption, and tooling costs. This study investigates the direct hydrogen reduction and sintering of metal–metal oxide extrusions designed to replicate the composition of 316L stainless steel. Extruded samples containing varying solids loadings and organic binders were characterized using X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and thermogravimetric analysis (TG) to monitor thermolysis, reduction and sintering. Full reduction of iron and nickel oxides was achieved at or before 950 °C, while chromium oxide formed spinel phases, reduced to chromium metal as a member of the iron solid solution, or remained as eskolaite (a polymorph of Cr2O3). The sintering temperature and time required for densification were correlated with extrudate composition; higher solids loading require a higher hold of 1250 °C, whereas lower solids content allows for a lower 1200 °C process temperature. Higher temperatures and longer dwell times resulted in a higher proportion of austenite compared to ferrite. This process enables fabrication of complex thin-walled geometries with reduced energy consumption and lower tooling requirements compared to traditional stainless steel manufacturing techniques. These results provide a foundation for extending hydrogen-based reduction to other alloy systems, including nickel-based superalloys, and highlight the potential for increased domestic, water-based emission metal production.